<div class="flip-clock">
    <ng-container *ngFor="let digit of time; let i = index">
      <div class="flip-unit">
        <div class="flip-card" [class.flip]="flip[i]">
          <div class="front">
            {{ time[i] }}
          </div>
          <div class="back">
            {{ nextTime[i] }}
          </div>
        </div>
      </div>
      <div class="separator" *ngIf="i === 1 || i === 3">:</div>
    </ng-container>
  </div>
